An Integral Heat Spreader (IHS) may be used, for example, as a component of semiconductor packaging, e.g., packaging of a processor, a “chip”, a controller, a memory unit, or another suitable device. An IHS may be formed, for example, of a single metal which may have high thermal conductivity (e.g., copper), and may be placed in proximity to a silicon die. The IHS may have a relatively high Coefficient of Thermal Expansion (CTE), for example, a CTE value of 15.5*10−6/°C. for a copper IHS. The silicon die may have a relatively low CTE, for example, a CTE value of 2.6*10−6/°C. Of course, other CTE values may be used.
The relatively high difference between the CTE value of the silicon die and other package components (e.g., a substrate) and the CTE value of the IHS may cause the assembled package may warp when the chip is powered up, or when the chip is thermally cycled (e.g., in an oven during the manufacturing process of the chip). The warping may result in various problems, failures, and reliability issues, for example, delamination of an adjacent Polymer Thermal Interface Material (PTIM), cracking of an adjacent Solder Thermal Interface Material (STIM), or other failures of the chip package. Furthermore, the warping may aggravate cracking of dielectric layers on the silicon die, and may even lead to the silicon die being torn apart.
To partially mitigate some of the above problems, a suitable Thermal Interface Material (TIM) layer may be used, for example, between an IHS and a silicon die. However, the TIM layer may be thick or relatively thick; this may result in, for example, a thick or a relatively thick package, and/or may lead to high or relatively high thermal resistance at the TIM layer. Additionally, the TIM may not adequately or completely solve all the above problems, failures and reliability issues.